diff options
| -rw-r--r-- | plat/qti/msm8916/aarch64/msm8916_helpers.S | 13 | ||||
| -rw-r--r-- | plat/qti/msm8916/aarch64/uartdm_console.S | 18 |
2 files changed, 17 insertions, 14 deletions
diff --git a/plat/qti/msm8916/aarch64/msm8916_helpers.S b/plat/qti/msm8916/aarch64/msm8916_helpers.S index dad9968ad..528c5a42e 100644 --- a/plat/qti/msm8916/aarch64/msm8916_helpers.S +++ b/plat/qti/msm8916/aarch64/msm8916_helpers.S @@ -1,5 +1,5 @@ /* - * Copyright (c) 2021, Stephan Gerhold <stephan@gerhold.net> + * Copyright (c) 2021-2023, Stephan Gerhold <stephan@gerhold.net> * * SPDX-License-Identifier: BSD-3-Clause */ @@ -31,17 +31,6 @@ */ func plat_crash_console_init mov x1, #BLSP_UART2_BASE - - /* - * If the non-secure world has been actively using the UART there might - * be still some characters left to be sent in the FIFO. In that case, - * resetting the transmitter too early might cause all output to become - * corrupted. To avoid that, try to flush (wait until FIFO empty) first. - */ - mov x4, lr - bl console_uartdm_core_flush - mov lr, x4 - mov x0, #1 b console_uartdm_core_init endfunc plat_crash_console_init diff --git a/plat/qti/msm8916/aarch64/uartdm_console.S b/plat/qti/msm8916/aarch64/uartdm_console.S index e14217939..6c65daf04 100644 --- a/plat/qti/msm8916/aarch64/uartdm_console.S +++ b/plat/qti/msm8916/aarch64/uartdm_console.S @@ -1,5 +1,5 @@ /* - * Copyright (c) 2021-2022, Stephan Gerhold <stephan@gerhold.net> + * Copyright (c) 2021-2023, Stephan Gerhold <stephan@gerhold.net> * * Based on aarch64/skeleton_console.S: * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved. @@ -65,7 +65,21 @@ endfunc console_uartdm_register * ----------------------------------------------------------- */ func console_uartdm_core_init - /* Reset receiver */ + /* + * Try to flush remaining characters from the TX FIFO before resetting + * the transmitter. Unfortunately there is no good way to check if + * the transmitter is actually enabled (and will finish eventually), + * so use a timeout to avoid looping forever. + */ + mov w2, #65536 +1: + ldr w3, [x1, #UART_DM_SR] + tbnz w3, #UART_DM_SR_TXEMT_BIT, 2f + subs w2, w2, #1 + b.ne 1b + /* Timeout */ + +2: /* Reset receiver */ mov w3, #UART_DM_CR_RESET_RX str w3, [x1, #UART_DM_CR] |